Support func matcher

README.md

@@ -70,6 +70,16 @@ app.use(proxy({
 }));
 ```
 
+Or you can use match of function style to exclude a specific path.
+```js
+app.use(proxy({
+  host:  'http://alicdn.com',     // proxy alicdn.com...
+  match: function match(path) { return /^(?!\/dontproxy\.html)/.test(path); } // ...everything except /dontproxy.html
+}));
+```
+
+
+
 Proxy won't send cookie to real server, you can set `jar = true` to send it.
 
 ```js

index.js

@@ -35,11 +35,17 @@ module.exports = function(options) {
 
     // if match option supplied, restrict proxy to that match
     if (options.match) {
-      if (!this.path.match(options.match)) {
+      var isMatched = false;
+      if (typeof options.match === 'function') {
+        isMatched = options.match(this.path);
+      } else {
+        isMatched = this.path.match(options.match);
+      }
+      if (!isMatched) {
         return yield* next;
       }
     }
-    
+
     var parsedBody = getParsedBody(this);
 
     var opt = {

test/index.js

@@ -203,6 +203,30 @@ describe('koa-proxy', function() {
       });
   });
 
+  it('shold have option host and match function', function(done) {
+    var app = koa();
+    app.use(proxy({
+      host: 'http://localhost:1234',
+      match: function(str){
+        return /^\/[a-z]+\.js$/.test(str)
+      }
+    }));
+    app.use(proxy({
+      host: 'http://localhost:1234'
+    }));
+    var server = http.createServer(app.callback());
+    request(server)
+      .get('/class.js')
+      .expect(200)
+      .expect('Content-Type', /javascript/)
+      .end(function (err, res) {
+        if (err)
+          return done(err);
+        res.text.should.startWith('define("arale/class/1.0.0/class"');
+        done();
+      });
+  });
+
   it('should have option followRedirect', function(done) {
     var app = koa();
     app.use(proxy({